This invention relates to a method for winding a spun or twisted thread on a bobbin and an electro-hydraulic traverse motion device, and more particularly to a method and apparatus for winding the thread on a bobbin by rotational movement of a shaft to rotate the bobbin and hydraulically controlling the traverse motion of a thread guide.
Many mechanical devices for reciprocating thread guides on spinning or twisting machines are known. In the devices, the essential functions work off a single drive. These include the traverse stroke, winding angle, edge displacement, stroke shortening and pattern interruption. These functions can be executed only in an inadequate manner and with substantial effort.
For a mechanical drive, the traverse stroke is determined by the geometry of a cylindrical cam. In order to operate with a different traverse stroke, the cylindrical cam must be replaced.
The sine of the winding angle is defined by the relationship of the traverse speed to the winding speed. Thus, the traverse speed is proportional to the feeding speed and can be modified only by modifying the proportionality factor. In mechanical traverse drives, this must occur in stages by means of a change gear, or continuously by means of an intermediate gear with continuous settings.
Edge displacement is necessary in order to wind on cylindrical bobbins at high speed and evenly over the entire length. In mechanical traverse drives, this usually requires an accessory drive that moves the cylindrical cam back and forth by the amount of the edge displacement.
Stroke shortening is necessary for winding on biconical bobbins. This function can be achieved by mechanical means only in a very complicated manner.
A pattern change should occur for avoiding winding resonance in the case of an accident and should also be avoided at both stroke ends. Often a winding disturbance is caused by a time-dependent on and off switching of a magnetic coupling located between the feeding drive and the reciprocating drive. However, a similar control is not provided which guards against accidental occurrence nor the suppression of a disturbed pattern at the stroke ends.
Hydraulic and/or electrical traverse motion devices and changing of gears are known which avoid, in part, the aforementioned disadvantages of mechanical changing gears. However, these function only in an inadequate manner and with great effort.
Accordingly, it is desirable to provide a method for winding a thread on a bobbin and an electro-hydraulic traverse motion device for its execution, whereby a simple hydraulic drive of thread guides can be accurately controlled through electrical selection of all functions required.